1. Field of the Invention
The present invention relates to a thermal transfer sheet to which a dye is transferred from an ink ribbon or the like according to a heat amount applied.
2. Description of the Prior Art
As a method for developing on a sensitized paper an image information entered into a video apparatus, there is a known method using a subliming dye or a thermal-melting dye.
In this thermal transfer method, a thermal transfer sheet (ink ribbon) having a dye layer formed is placed on a thermally sensitized sheet having a reception layer for receiving the dye so that the dye layer is opposed to the reception layer, and a thermal head or the like is used to apply a heat in dot shapes according to an image signal. Thus, the dye in the dye layer sublimes or is melted to move to the reception layer of the sensitized paper and image appears on the sensitized paper.
However, the conventional thermally sensitized sheet has a problem that the image formed does not have a sufficient light resistance or weather resistance. That is, the image formed becomes unclear or discolored. The reason is considered to be as follows: the dye which is transferred by a thermal head or the like is located in the vicinity of the surface of the reception layer and easily affected by humidity and oxygen in the air.